public class User{
  public String id;
  public String username;
  public String password;
  
  //无参构造器
  public User(){
  }
  
  //全参构造器
  public User(String id,String username,String password){
      this.id = id;
      this.username = username;
      this.password = password;
  }

  //id属性的setter和getter方法
  public void setId(String id) {
      this.id = id;
  }

  public int getId() {
        return id;
    }

    // username 属性的 setter 和 getter 方法
    public void setUsername(String username) {
        this.username = username;
    }

    public String getUsername() {
        return username;
    }

    // password 属性的 setter 和 getter 方法
    public void setPassword(String password) {
        this.password = password;
    }

    public String getPassword() {
        return password;
    }
}